The present invention related to electrophysiology (electroencephalography, class 128, subclass 2.1 B), and more particularly to the testing of neural mechanisms of learning and memory to quantitatively diagnose brain dysfunction.
It is known that specified conditions or stimuli may be used to evoke brain electrical activity, which may be detected, indicating the subject's response or non-response to the stimuli. The evoked responses may be quantitatively interpreted by "challenges" which specify analytic protocol.
An article by Shigeru Yosida et al, July 1975, Electroencephalography and Clinical Neurophysiology, states that the averaged evoked response produced by a stationary grating of alternating high dark-bright contrast was less in amplitude when it was presented obliquely than when it was oriented horizontally or vertically. Additionally, the amplitude varied on oblique orientation. However, this test indicated only that vertical and horizontal orientation elicit larger responses in that they are identifiable or the brain is more certain of their orientation. The brain recognizes vertical and horizontal orientations but assimilates oblique orientations. Even assuming an even number of dark and bright areas, 180.degree. rotation would produce only minimal pattern reversal and is clearly of insignificant meaning as a control for that purpose.
In the U.S. Pat. No. 3,780,274 entitled "Sensation-Cognition Computer" there is disclosed quantitative electrophysiological tests having the three general components. These three general components are: (i) a sensory stimulus is presented to the subject, such as a series of light flashes in a defined order; (ii) a recording is made of the subject's brain waves in response to the stimulus; and (iii) a computer-based digital analysis of the responsive brain waves compares the subject's responses to values obtained from testing of prior subjects. The tests described in that patent are of ordered sequence vs. random sequence; predictable pattern and its alternation; habituation and dishabituation to the same meaningless stimulus; and conditioning using different senses and presentation of different geometric designs.
The U.S. Pat. No 3,906,644 entitled "Method of Presenting Reading Material To Dysmetric Dyslexic-Identified Children" discusses the problem of letter reversals and confusion of words and letters which differ in spacial placement.